There is a filthy underworld the government has failed to confront. For once, the word "filthy" is not meant metaphorically. This filth is the cloud of poisonous smoke from piles of tyres being illegally burned; the pollution of water supplies by rotting nappies, batteries and other household waste; the toxic waste left in leaking canisters in a park where children play.

Much of Britain looks clean enough - the well-kempt villages and suburbs, the national parks and even regenerated city centres. But the country is criss-crossed by lorries and vans sneaking off to do some illegal dumping, and one of the best indices of poverty is where they end up.

Struggling housing estates are vastly more vulnerable to the fly-tippers and the cowboys of industrial waste than middle-class communities. Yet this is not only about poor estates - no one can escape the effects of air or water pollution, often undiscernible until it is too late.

Are there no laws? Yes, but they are barely enforced. The Environment Agency reckons that of 30,000 offences a year, of which around 1,300 are really serious, only 700 are prosecuted. And even then, when fines are handed down, they barely touch the companies involved. In one recent case, an Oxfordshire man was fined £30,000 for abandoning 184 drums of toxic waste: but he was paid nearly twice as much to do it and the authorities had to spend £167,000 cleaning up the mess. In Cwmbran a waste company operating illegally was fined £25,000 but had made ten times as much by doing so.

Imprisonment is virtually never used for company directors who foul the environment; magistrates are under-trained in this area; these crimes are often delayed in court to deal with more conventional offences which get greater publicity... in short, it's a mess. In many ways it is a problem which mirrors other government failures. There have been plenty of fine words, even laws. But actually changing things on the ground? No.

Harriet Harman, the solicitor general, will be arguing later today for a manifesto commitment to a new approach, the environmental equivalent of anti-social behaviour orders, making it easier to force polluting companies to clear up their own mess, and to work with the communities they have dirtied.

She argues that it's hardly a marginal issue - last year some 48,000 people complained to the Environment Agency about pollution of water supplies, outflows of untreated sewage into people's gardens, and toxic clouds.

It is a proposal that is now being discussed by the "green" ministerial group, drawn from different departments and coordinated by the environment minister, Elliot Morley. But how, I wonder, will Tony Blair and the No 10 lot react to it? There are signs, say environmental campaigners, of a yawn behind the hand.

In some areas the prime minister has certainly "got" the green agenda. This year's G8 agenda isn't only about Africa, though sometimes you would think so: Mr Blair's other main concern, he says, is global warming and therefore the attempt to win over Washington to some kind of new agreement on carbon emissions. It may be the single most important political issue facing the world.

And right at the other end of the scale, the government has been increasingly active on local environmental issues - littering, graffiti and abandoned cars. There's a clean neighbourhoods and environment bill going through the Commons at the moment, which allows greater use of fixed penalty notices, for instance.

This is very much the Blair style, with all its strengths and weaknesses. Big on the global vision, ready with grand initiatives for the world stage, and sensitive too to the most immediate, local concerns of relatively unpolitical voters, the complaints that fill the letters pages of local newspapers.

Fair enough; but it leaves a large gap: how to deal with polluting businesses. For every proposed new law there will be a Downing Street adviser muttering about the dangers of over-regulation. It is an area in which Blair's conservatism is turned up high.

So industrial pollution could be seen as a litmus test. It overwhelmingly affects poorer communities. It is resolutely unsexy as an issue. It has an ideological edge, since it means the state taking on "entrepreneurs" and British businesses. And yet it is a huge issue for large numbers of people whose lives are made a misery, far away from the trimmed, well-ordered places where most politicians, journalists and advisers live.

There are political warnings to be spotted. Ministers are being warned that, as part of a wider problem of disaffection on the left, Labour MPs are increasingly vulnerable to Liberal Democrat and even Green campaigns.

It shouldn't take that to kick-start interest in this, though. For all the problems, New Labour is establishing itself as contemporary Britain's natural party of government. That means being responsible, over decades, for the condition of the country. And we still are a dirty, often filthy, country.